In recent decades, air pollution caused by fine particulate matter (PM₂.₅) has emerged as one of the most critical environmental challenges in urban an‎d industrial regions. Due to their high penetrability into the respiratory system an‎d their ability to carry potentially toxic elements (PTEs) such as Pb, Cd, As, Ni, an‎d Cr, these particles pose serious health risks, including carcinogenic effects. Identifying the sources of these elements an‎d assessing their environmental an‎d human health risks are essential for effective pollution management an‎d policy development. This study investigates the concentration, source apportionment, an‎d risk assessment of PTEs associated with PM₂.₅ in the Pars Special Economic Energy Zone. Over a one-year period (from December 2023 to October 2024), 192 24-hour samples were collected from three monitoring stations including Bidkhun, Nakhl-e-Taghi, an‎d Siraf. PTE concentrations were measured using ICP-MS, an‎d pollution indices such as the geo-accumulation index (Igeo), enrichment factor (EF), contamination factor (CF), pollution load index (PLI), an‎d ecological risk index (RI) were calculated. Human health risks were also eva‎luated using non-carcinogenic an‎d carcinogenic risk indices. Source apportionment was conducted using positive matrix factorization (PMF) an‎d principal component analysis (PCA). Results indicated that the annual average concentration of PM₂.₅ at all three stations exceeded national limits an‎d EPA stan‎dards. The highest annual average was recorded at Bidkhun (43.1 µg/m³), followed by Nakhl-e-Taghi (38.1 µg/m³) an‎d Siraf (38.4 µg/m³), with the highest value of 72.7 µg/m³ in August at Bidkhun. Pollution indices suggested natural origins for elements such as Al, Fe, an‎d Mn, while elements like Zn, Cu, Pb, Cd, Mo, an‎d Ni were primarily anthropogenic. EF for Cd an‎d Mo exceeded 40 in some samples, indicating extremely high enrichment. Ecological risk indices were very high across all stations, an‎d non-carcinogenic risk for children exceeded the threshold of concern. The carcinogenic risk index for As also surpassed acceptable levels, mainly due to industrial sources such as gas flaring an‎d petrochemical industries. PMF modeling identified five major sources contributing to the PTEs mass in PM₂.₅ including natural sources (44–55%), transportation (31–32%), petrochemical activities (5–8%), gas flaring (3–6%), an‎d other industrial sources (5–14%). These findings were consistent with PCA results. Notably, elements with higher ecological an‎d health risks (e.g., Cr, As, Co, Pb, Cd, Ni, an‎d V) were predominantly from industrial origin, despite their lower mass contribution compared to naturally derived elements (e.g., Ti, Fe, Mn, an‎d Sr). Overall, the findings indicate that the study area is influenced by a combination of natural an‎d anthropogenic sources of PTEs, with industrial emissions posing a significant threat to public health an‎d the environment. Continuous monitoring an‎d implementation of emission control measures are therefore imperative.

محسن سليماني امين آبادي

Jan H. Christensen , Peter E. Holm

نوراله ميرغفاري , محمد نعمتي ورنوسفادراني